The diaminodimethylbiphenyl starting material used to prepare the heterocyclic peri acids of the present invention were reported by Carlin and Foltz in the Journal of the American Chemical Society, Vol. 78, pages 1997 to 2000, May 5, 1956. Carlin et al prepared the diaminodimethylbiphenyl by reacting aminonitrotoluene with potassium iodide in the presence of sodium nitrite to produce iodonitrotoluene. The iodonitrotoluene was heated in the presence of copper powder forming dinitrodimethylbiphenyl by an Ullmann coupling reaction. Exposure of the dinitrodimethylbiphenyl to hydrogen in the presence of a Raney nickel catalyst hydrogenated the nitro substituents to amino substituents thereby forming diaminodimethylbiphenyl. The reaction mechanism is illustrated as follows: ##SPC3##
Biquinoline compounds of the present invention may be used in high performance heterocyclic ladder polymers. Examples of polymers similar to those in which these biquinoline compounds may be used have been reported in the Journal of Polymer Science, Vol. 6, pages 1777 to 1793, (1968) and Vol. 8, pages 2079 to 2089, (1970).